This patent application claims priority based on a Japanese patent application, H11-290189 filed on Oct. 12, 1999, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an ink cartridge detachably attached to a printing apparatus and supplying ink to a printhead of the printing apparatus which ejects ink droplets in accordance with a printing signal.
2. Related Art
Typically, a printhead of an ink-jet printing apparatus connects with an ink cartridge via an ink supply channel. The printhead is designed to receive ink from the ink cartridge. The printing apparatus is provided with a hollow ink supply needle in the ink supply channel to supply ink to the printhead. The ink cartridge is formed with an ink supply port for supplying ink to the printhead. When the ink cartridge is mounted on the printing apparatus, the hollow ink supply needle is inserted into the ink supply port of the ink cartridge and ink is supplied to the printhead via the hollow ink supply needle.
Unexamined Japanese patent applications (OPI) Nos. Hei. 5-229137 and Hei. 9-174879 disclose an ink cartridge of this structure including a valve member at an upper part of the ink supply port, i.e., inside of the ink cartridge. The ink supply port of the ink cartridge of this type opens when the ink supply needle is inserted, and closes when the ink supply needle is removed. Thus, the ink cartridge is capable of preventing leakage of ink or is capable of being repeatedly attached to the printing apparatus. On the other hand, Unexamined Japanese patent application (OPI) No. Hei. 7-232438 discloses an ink cartridge having a semiconductor memory device that stores data relating to the ink cartridge.
The conventional valve member as mentioned above, however, has a drawback as the connection between the semiconductor memory device of the ink cartridge and a control unit of the printing apparatus is inadequate. More specifically, as the valve member is always urged by a spring in an insertion direction of the ink supply needle in order to seal the ink supply port, the ink cartridge does not completely fit to a carriage of the printing apparatus because the resilient force of the spring pushes the cartridge up to some extent with respect to the carriage after the ink cartridge is mounted on the carriage. Such results in that the accurate positioning of the ink cartridge with respect to the carriage is hardly accomplished, and if a memory device is mounted on the ink cartridge, the connection of terminals of the memory device to the contact member of a circuit unit of the printing apparatus may be failed due to the deviation caused by the resilient force of the spring urging the valve member.
Further, if the conventional ink cartridge is detached from the carriage of the printing apparatus to exchange to a cartridge of different kind or type while the original ink cartridge is not depleted, the ink may leak out of the ink cartridge through the ink supply port. Such a problem would be more emphasized when the ink cartridge is recycled and the valve or packing becomes worn out and, accordingly, the sealability of the valve mechanism is deteriorated.
In addition, if the memory device comes into contact the terminal of the printing apparatus whereas the ink supply needle does not correctly enter the ink supply port and thus still not ready for supplying ink, the printing operation may start and air would be conveyed to the nozzles of the printhead. Such could result in a serious problem in giving damage to the printhead, and no recovery can be expected without exchanging the printhead. Therefore, it has been required an appropriate interrelationship of the contact electrode of the memory device with the engagement between the ink supply port and the ink supply needle.
The present invention was made in view of the foregoing drawbacks accompanying the conventional ink cartridge. Therefore, it is an object of the present invention to provide an ink cartridge capable of performing an adequate connection between a memory device mounted on the ink cartridge and an external circuit unit, regardless of a reactive resilient force of a spring for urging a valve, so that the memory device of the ink cartridge is capable of electrically connecting in a stable manner with the external circuit unit.
Another object of the present invention is to provide an ink cartridge capable of preventing ink from leaking out through the ink supply port even though the ink cartridge is detached from the printing apparatus for exchanging while ink is not depleted.
Still another object of the invention is to provide an ink cartridge capable of achieving an appropriate interrelationship of the contact electrode of the memory device with the engagement between the ink supply port and the ink supply needle.
The above and other objects can be attained by a provision of an ink cartridge for an ink jet printing apparatus having a printhead which ejects ink droplets onto a recording medium and an ink supply needle introducing ink to the printhead which, according to the present invention, includes: a substantially rectangular housing for containing ink therein, said housing having a first outer wall and a second outer wall which is substantially perpendicular to said first outer wall; an ink supply port formed in said first wall for directing ink in said housing to the printhead; a valve mechanism arranged in said ink supply port comprising: a valve seat allowing the ink supply needle to pass therethrough; a valve body movable along the axis of said ink supply port; and an elastic member biasing said valve body against said valve seat, and a memory device for storing information relating to ink mounted on said second wall of said housing and substantially in parallel therewith, said memory device being arranged in the vicinity of said ink supply port, and said second wall extending in a direction parallel with a direction along which the ink supply needle is insertable into said valve seat, said memory device comprising a substrate and a plurality of electrode terminals arranged on one surface of said substrate.
The memory device may be disposed on a center line of the second wall of the housing. The second wall may have a projection which engages with a hook of an ink cartridge holder of the printing apparatus. The housing may be formed with a concave portion in which the memory device is accommodated. The ink cartridge according to any one of the preceding claims, wherein the housing comprises a plurality of ink chambers for different ink, each chamber comprising an ink supply port, and the memory device is disposed substantially at a center of the total width of the plurality of ink chambers. The memory device comprises a substrate, a plurality of electrode terminals arranged on one surface of the substrate and a storage device disposed on the other surface of the substrate. According to the invention, the memory device may include: a substrate; an electrode terminal arranged on one surface of the substrate at a position where the terminal electrically connects to a contact member of the printing apparatus when the ink supply needle is inserted into the valve seat up to a regular position where the ink supply needle feeds ink; and a storage device secured on the substrate, the storage device communicating with the printing apparatus when the ink cartridge is mounted on the printing apparatus.
According to the invention, the length of the terminal along the direction of insertion of the ink supply needle into the valve seat is longer than the maximum length of entry of the ink supply needle into the ink supply port from the valve seat, subtracted by a length that the ink supply needle is pushed back by a resilient force of the elastic member as a reactive force thereof generated by urging the valve body. The terminal starts to connect electrically with the contact member of the printing apparatus when the tip end portion of the ink supply needle comes into contact with the valve body. The terminal along the direction of insertion of the ink supply needle into the valve seat is longer than the length that the ink supply needle slides into the housing while pushing the valve body against the elastic member. The housing comprises a cover plate, the cover plate includes: a through-hole; an elongated groove which is in fluid communication with the inside of the housing through the through-hole; and a film covering the top of both the through-hole and the groove so that air flows through the groove and the through-hole into the housing.
The ink cartridge further includes a cylindrical packing member disposed in the ink supply port for communicating an interior of the housing with the printhead through the ink supply needle, wherein the valve body of the valve mechanism is disposed at the housing side of the cylindrical packing member, and always urged by the elastic member to seal the cylindrical packing member. The ink cartridge may further includes a porous member accommodated in the housing for holding ink. A capillary force of the porous member is greater in the vicinity of the ink supply port than other parts of the porous member.
According to another aspect of the invention, the above objects can be achieved by a provision of an ink jet printing apparatus which includes: a printhead for ejecting ink droplets onto a recording medium; and an ink container supplying ink contained therein to the printhead, the ink container comprising: a first wall; a second wall; and an ink supply port formed in the first wall for directing ink in the ink container to the printhead; an ink supply needle for feeding ink from the ink container to the printhead by being inserted into the ink supply port; a valve mechanism arranged in the ink supply port comprising: a valve seat allowing the ink supply needle to pass therethrough; a valve body movable along an axis of the ink supply port; and an elastic member biasing the valve body against the valve seat; and a memory device for storing information relating to ink disposed on the second wall of the container, which second wall extends in a direction parallel with a direction along which the ink supply needle is inserted into the ink supply port, the memory device comprising a substrate and a plurality of electrode terminals arranged on one surface of the substrate.
According to still another aspect of the invention, an ink cartridge for an ink jet printing apparatus includes: a cylindrical packing member in an ink supply port thereof for communicating an ink chamber with a printhead through an ink supply needle; and a memory device having electrodes for connection, wherein said electrodes for connection accomplish a conductive relation with external contacts under a condition where the ink supply needle assuredly engages with the cylindrical packing member to allow ink to be supplied.
According to still another object of the invention, the above objects can be achieved by a provision of an ink cartridge communicating an ink chamber with a printhead through an ink supply needle and comprising a re-seal structure arranged in an ink supply port thereof, in which the ink cartridge includes a memory device for storing thereon information relating to the ink cartridge and a porous member for holding ink arranged at the ink chamber side of the re-seal member.
The ink chamber communicates with ambient air through a capillary action formed in a surface of the cartridge body. The re-seal structure is capable of supplying ink to the printhead in response to a negative pressure applied from the printhead, a porous member for holding ink is disposed, and a packing member is formed at the ink chamber side with a slit which is openable by the insertion of the ink supply needle.
According to still another object of the invention, the above objects can be attained by a provision of an ink cartridge for an ink jet printing apparatus which comprises a cylindrical packing in an ink supply port thereof for communicating an ink chamber with a printhead through an ink supply needle, wherein a valve body is disposed at an ink chamber side of the cylindrical packing, and always urged by a spring to seal the cylindrical packing, and a memory means, having electrodes for connection, is disposed on a wall of the ink cartridge, which wall being in parallel with an insertion direction of the ink supply needle.
The memory means is disposed on a wall which is in the vicinity of the ink supply port. The memory means has a region on which data of ink consumption amount is stored. The memory means has a region on which a recycling information of the ink cartridge is stored. The memory means may have one surface forming a front surface on which the electrodes for external connection are formed and a rear surface on which a semiconductor storage means is installed. Further, a porous member is housed in the ink chamber at least in the vicinity of the valve body. A porous member is housed in the ink chamber and a filter is provided upstream of the valve body. In addition, a cover plate for sealing an upper part of the ink chamber is formed with an air hole which communicates with ambient air through fine grooves formed in the surface of the cover plate.